Download SIDE BONE - Darmanin Farriery Malta

The term “side bone” describes collateral cartilages that hardened into
bone. Side bone is a common condition in horses, depicted by the
ossification (that is the process of laying down new bone material), of
the collateral cartilages of the coffin bone (also known as the distal
phalanx, third phalanx, P3, or pedal bone). The collateral cartilages are
found on the medial (inside) and lateral (outside) sides of the hoof and
can be palpated just above the level of the coronary band, as flexible
projections on each side of the lower pastern.
The collateral cartilages are an important part of the anti-concussion
mechanism which acts as a shock absorbers for the foot. This anticoncussion mechanism incorporate the frog, the navicular bone, the
flexibility of the hoof wall and the collateral cartilages. Because
cartilages are normally elastic, allowing the foot to deform during weight
bearing, and then return to its usual shape. Once ossified the cartilages
transform into much harder and less flexible structures.
Side bone can develop in the front and / or hind feet, but the front feet
are most commonly affected.
Causes of Side Bone
Repeated concussion of the foot on hard surfaces is the primary cause in
many cases. Such concussion occurs when horses are constantly worked on
hard uneven terrian.
It could also be the „not so ideal‟ or poor conformation hereditary
factors. Poor conformation include:- horses with narrow upright feet,
horses with unbalanced feet, especially if they have toe-in or toe-out
conformation. Abnormal limb conformation which may cause uneven
forces on the collateral cartilage.
Draft or heavy build horses are more likely to develop side bone condition
than light breeds or ponies.
Irregular shoeing may cause the foot to land unevenly consequently
excessive wear on one side of the shoe, resulting in concussion on one
part of the foot.
Furthermore direct trauma to the collateral cartilages may also lead to
side bone formation.
Symptoms Associated with Side Bone
Side bone may be associated with lameness but many horses with side
bone are not lame. The stride may be shortened, and walking the horse
across a slope may amplify the soreness. Lameness may be a sign,
depending on the stage of ossification, the amount of concussion
sustained by the feet, and the standard of terrain. Lameness is most
likely when side bone is associated with a narrow or contracted foot.
Diagnosis (identification) of Side bone
Careful examination of the collateral cartilages by palpation can give an
indication that cartilages are hard and boney rather than firm and supple.
Usually, however, side bone is found when the foot is radiographed. X-ray
examinations will reveal bone formation in the cartilages. In most cases
side bone has few outward signs but examination of the cartilages will
revel that hardening is present. Firm pressure on the cartilages will
cause the horse to flinch. In some cases there will be a visible bulging of
the quarters at the coronary band.
Treatment of Side bone
Side bone usually does not cause any problems, but where it does it is
difficult to treat. Many horses remain active with side bone condition and
are not hindered in any way. If the ossification is severe and associated
with lameness then box rest and non-steroidal anti-inflammatory drugs
such as Bute may be useful to relieve pain. It is important to be careful
with exercise. If the horse is in pain and goes lame give him as much time
off as necessary. In some cases the only useful treatment is a
neurectomy that is the surgical removal of a nerve or part of a nerve of
the palmar digital nerves.
Within this condition the contested heel expansion theory is much
debated. But from experience the gradually heel expansion seems to be
essential in the treatment. The affected foot should be re-shod
regularly to gradually encourage heel expansion.
Skilled trimming of the hoof with remedial shoes will assist the horse
with this condition. The horse should be shod with a wide-web shoe with
rolled toe. Avoid to drive-in nails behind the mid-quarters of the shoes.
Remedial shoes such as a rolled toe side bone shoe will decrease the
break over forces in the coffin joint region. A side bone shoe is made
from flat bar and is plain stamped. Ground surface bevelled and rolled to
ease break over and pressure on side bone.
The toe is bent and the outside branch formed. The outside branch is
then chamfered on the ground surface towards the outside, retaining the
thickness of the inner edge. The chamfering, which has the effect of
broadening the web, should be greatest at the heel and gradually reduced
towards the toe.
Rolled-toe or rockered-toe shoe, square off the toe, or even consider the
squared-off-behind-the-toe design of a natural balance shoe. Anything
which moves the break over back is good.
Shock absorbing pads are
beneficial too. Continuous assessment of the shoe wear must be carried
out to ensure that the horse is becoming sound after having side bone.
Levelling out any medial and lateral imbalances to ensure that the foot
lands level, lessening concussion on either side of the foot.